In many surgical procedures it is often necessary to ligate a plurality of vessels in the surgical site. The vessels may then be severed down-stream of the ligated portion. In some instances the vessel may be ligated at spaced apart areas and the portion of the vessel between the ligations removed. The primary reason for ligating the vessels is to maintain the surgical site free from an excess of blood and to reduce blood loss in the patient. Also, in certain surgical procedures wherein tumors or parts of organs and the like are to be removed, the tumor or organ may have to be separated from certain vessels, and before separating the vessels will have to be ligated.
In the past, the closing of the vessel was usually accomplished using ligatures; that is, threads or filaments which the surgeon ties around the vessel desired to be closed, a very time consuming process and one in which positive closure of the vessel is not always accomplished. In relatively recent years hemostatic clips have replaced the ligatures in many surgical procedures to close blood vessels and other small fluid ducts. These hemostatic clips have been narrow U-shaped or V-shaped strips made from tantalum or stainless steel which are capable of being deformed and possess sufficient strength to retain the deformation when clamped about a blood vessel.
Representative hemostatic clips of the prior art are best illustrated in U.S. Pat. Nos. 3,867,944, 3,631,707, 3,439,523, 3,439,522, 3,666,628, 3,312.216, and 3,270,745.
Very recently the hemostatic clips made from absorbable or non-absorbable polymeric materials have been developed and are being used in various surgical procedures. These polymeric hemostatic clips are more fully described and disclosed in copending patent applications Ser. No. 282,461 filed July 13, 1981, now U.S. Pat. No. 4,418,694, and Ser. No. 276,131 filed June 22, 1981, now abandoned.
The polymeric clips described generally comprise a pair of leg members attached in some manner at their proximal ends. Very often this attachment is in the form of a resilient hinge portion although other means of attachment may be used. The leg members contain smooth innersurfaces disposed towards one another and called the vessel clamping surfaces. It is these surfaces which contact the vessel and close the vessel when the clip is closed. The distal ends of the leg member terminate in an interlocking latch means. The latch means must extend beyond the vessel to be clamped and clear the vessel in order to lock.
Unlike the metal clips which may be deformed about a vessel, the polymeric hemostatic clip as described above latches over the vessel and, hence, surrounds the entire vessel. This means that to use such clips made from the absorbable or non-absorbable polymeric materials, the vessel to be ligated must be free or fully dissected from the surrounding tissue so that the clip may entirely encircle the periphery of the vessel. In many surgical procedures there are a number of small vessels and for the surgeon to have to fully dissect these vessels is a very time consuming process. With the metal clip the surgeon does not have to dissect these vessels but can place the clip on the vessel and about surrounding tissue and deform the clip so that it closes the vessel. This is not true with the clips made from polymeric materials.
An object of the present invention is to produce a clip from absorbable and non-absorbable polymeric materials which may be used to close vessels which have not been fully dissected from the surrounding tissue.
Another object of the present invention is to reduce the time required in a surgical procedure to place hemostatic clips made from polymeric materials.
It is yet another object of the present invention to produce a hemostatic clip from polymeric materials wherein the clip has a latch means that can part the tissue and engage and lock the clip about the vessel although there is tissue adjacent the vessel to be closed.
These and other objects of the present invention will be more fully understood from the following description and drawings.